Feed system for plasma-arc furnace

Abstract

According to the invention, there is proposed a feed system for a plasma-arc furnace wherein an electrode with an axial opening is used as the low-temperature plasma generating means. The feed system comprises a gas conduit, in the form of an individual water-cooled member, a current-conducting element mounted within a shell and secured to a flange which includes a duct for the delivery of gas, a duct for feeding flux, and a duct for supplying water. The flange has secured to it the shell. A flux delivery means and a bus for power supply are also included. The herein proposed feed system makes it possible to assure stable operating conditions of a plasma-arc furnace, enhance its efficiency, reduce power losses and decrease expenses involved in the remelting of metals and alloys.

What is claimed is: 
     
       1. A feed system for a plasma-arc furnace provided with an electrode having an axial opening and used as the low-temperature plasma generating means, said feed system comprising: a gas conduit coaxially aligned with said electrode;   a current-conducting element coaxially aligned with said gas conduit;   a shell housing said current-conducting element and said gas conduit;   a fixing assembly for coupling said electrode to said gas conduit, said fixing assembly including two connecting pieces and a clamping ring, said connecting pieces being fitted around said shell and said electrode, and said clamping ring being secured around said connecting pieces;   a means for the delivery of flux to a melting zone of said plasma-arc furnace;   a flange having secured to it said shell and said flux delivery means, said flange having a duct for delivering gas, a duct for supplying water and a duct for feeding flux.   
     
     
       2. A plasma-arc furnace feed system as claimed in claim 1, wherein the length of said gas conduit exceeds that of said shell by an amount less than twice the diameter of said gas conduit. 
     
     
       3. A plasma-arc furnace feed system as claimed in claim 5, wherein said fixing assembly is provided with a diaphragm and seals, said diaphragm being arranged between said connecting pieces intermediate of said shell and said electrode, one of said seals being disposed in an interspace between said shell and said diaphragm, and another of said seals being disposed between said electrode and said diaphragm. 
     
     
       4. A plasma-arc furnace feed system as claimed in claim 2, wherein said fixing assembly is provided with a diaphragm and seals, said diaphragm being arranged between said connecting pieces intermediate of said shell and said electrode, one of said seals being disposed in an interspace between said shell and said electrode, and another of said seals being disposed between said electrode and said diaphragm. 
     
     
       5. A plasma-arc furnace feed system according to claim 1, wherein said current-conducting element is a hollow cylinder. 
     
     
       6. A plasma-arc furnace feed system according to claim 3, wherein said diaphragm is a thin-walled frustoconical member. 
     
     
       7. A plasma-arc furnace feed system according to claim 4, wherein said diaphragm is a thin-walled frustoconical member.